Vehicle for running on rail

ABSTRACT

A vehicle for running on rail is provided, which has the capability of achieving smooth running, while moderately gripping the rail. This vehicle has a base, a pair of first and second wheels held by the base to be rotatable on an upper surface of the rail and spaced from each other in an extending direction of the rail, a third wheel held by the base to be rotatable on a lower surface of the rail, and a motor for rotating the first wheel. The first wheel is positioned between the second and third wheels in the extending direction of the rail, and the second wheel is held by the base through a cushioning member. When the vehicle is tilted due to an elastic deformation of the cushioning member for the second wheel, gripping forces of the first and third wheels on the rail increase.

TECHNICAL FIELD

The present invention relates to a vehicle for running on rail (tracked vehicle), and particularly the vehicle having the capability of providing smooth running, while moderately maintaining a grip force on the rail.

BACKGROUND ART

In a vehicle for running on rail, there is a case that a reduction in grip force that is friction resistance between a drive wheel and the rail poses a problem for the vehicle's running. For example, slippage easily occurs on the rail in the rain. In particular, when the vehicle runs on an inclined rail in the rain, it becomes a serious problem.

To solve this problem, it is needed to increase the grip force by pressing the drive wheel against the rail. However, an excessive increase in the grip force leads to an increase in energy needed for the vehicle's running. As a result, it becomes difficult to provide efficient running of the vehicle on the rail.

In addition, to obtain a moderate grip force, it has been proposed to monitor a weight of the vehicle by a weight sensor, and control a spring constant of a spring member for pressing the wheel against the rail according to the monitored weight. However, there are problems that the control becomes complex, and a total cost of the vehicle track system increases.

In addition, Japanese Patent Early Publication [kokai] No. 3-70670 discloses a track device system with a running unit for running on a rail. As shown in FIG. 9, the running unit 100 used in this device has a drive wheel 110 rotatable on an upper surface of the rail 1, and a pair of auxiliary wheels 120 rotatable on a lower surface of the rail, and has the capability of running, while holding the rail between the drive wheel and the auxiliary wheels. A curve region of the rail is designed to be different in rail width from a straight region of the rail such that an overlapping amount between the auxiliary wheel and the lower surface of the rail is not larger than a constant value. Thereby, it is possible to prevent that an excessive reaction force loads on the drive wheel 110 and the auxiliary wheels 120, and provide smooth running on the rail 1.

However, in such a track device, it is needed to manufacture the rails having different widths every curve region. Therefore, when a total length of the rail is long, or many curve regions are designed in the track device, an increase in cost of the track device is unavoidable.

Thus, from the viewpoints of considering the cost performance of the entire track device, and providing smooth running of the vehicle, while moderately maintaining the grip forces of the wheels on the rail, there is still plenty of room for improvement in the conventional vehicle for running on rail and the system using an expensive control unit or the design change of the rails.

SUMMARY OF THE INVENTION

In view of the above problems, a primary concern of the present invention is to provide a vehicle for running on a rail having the capability of moderately generating a grip force of a wheel (drive wheel) on the rail according to a total weight of the vehicle (including loads), and realizing efficient and smooth running, despite its relatively simple structure.

That is, this vehicle has a base; a pair of first and second wheels held by the base to be rotatable on an upper surface of the rail and spaced from each other in an extending direction of the rail; a third wheel held by the base to be rotatable on a lower surface of the rail; and a motor for driving at least one of the first and second wheels. The first wheel is positioned between the second wheel and the third wheel in the extending direction of the rail, and the second wheel is held by the base through a cushioning member.

According to the present invention, when the cushioning member such as a coil spring is elastically deformed downward by receiving a weight of the vehicle and loads carried on the vehicle, the vehicle takes an inclined posture such that the second wheel side having the cushioning member of the base comes close to the rail. At this time, the third wheel positioned at a side opposed to the second wheel through the first wheel is pressed against the lower surface of the rail according to the principle of leverage with a fulcrum that is the contact point between the first wheel and the rail. Thereby a force for holding the rail between the first wheel and the third wheel, i.e., the gripping force is obtained. In addition, since an amount of the elastic deformation of the cushioning member, i.e., an inclination degree of the vehicle changes according to the weight of received from the vehicle, the rail gripping mechanism of the present invention can provide a moderate gripping force according to the vehicle's weight. Therefore, when the elastic deformation capability of the cushioning member and the position of the third wheel are appropriately determined, it is possible to provide the moderate gripping force between the wheel and the rail according to the weight of the vehicle (including the loads) without using a special device for monitoring the vehicle's weight and controlling the spring constant of the spring member for pressing the wheel against the rail according to the monitored weight. As a result, it is possible to provide efficient and smooth running of the vehicle.

In a preferred embodiment of the present invention, a distance between the first wheel and a center of gravity of the vehicle in a running state is greater than the distance between the second wheel and the center of gravity, and shorter than the distance between the third wheel and the center of gravity. In this case, since the second wheel is disposed in the vicinity of the center of gravity of the vehicle, the cushioning member can be elastically deformed more effectively at a slope region of the rail to obtain the gripping force.

In addition, it is preferred that the third wheel is comprised of at least two wheels spaced from each other in the extending direction of the rail. In this case, since the plural third wheels contact the lower surface of the rail, it is possible to increase the friction resistance, and further improve the gripping performance on the rail.

Moreover, it is preferred that the vehicle has an auxiliary wheel held by the base to be rotatable on a side surface of the rail under at least one of the first and second wheels. In this case, since the first and second wheels are guided to prevent derailment, the running safety of the vehicle can be further improved.

Further features of the present invention and effects brought thereby will be clearly understood from the best mode for carrying out the invention described below, referring to the attached drawings.

BRIEF EXPLANATOIN OF THE DRAWINGS

FIG. 1 is a side view of a vehicle for running on rails according to a preferred embodiment of the present invention;

FIG. 2 is a top view showing a seat arrangement in the vehicle;

FIG. 3 is a partially enlarged view showing a wheel arrangement of the vehicle;

FIG. 4 is a view showing first and third wheels of the vehicle on the rails;

FIG. 5 is a view showing second wheels of the vehicle on the rails;

FIGS. 6A and 6B are conceptual diagrams illustrating the principle of generating a gripping force of the vehicle of the present invention on the rail

FIG. 7 is a side view of the vehicle running in a slope region of the rail;

FIG. 8 is a side view of a modification of the vehicle of FIG. 1; and

FIG. 9 is a conceptual diagram of a conventional track device.

BEST MODE FOR CARRYING OUT THE INVENTION

A vehicle for running on rails of the present invention is explained in detail according to preferred embodiments, referring to the attached drawings.

As shown in FIGS. 1 and 2, the vehicle 10 for running on rails of this embodiment has the capability of running on a pair of rails 1 extending in parallel to each other in the forward and backward directions. The vehicle is formed with a base 11, a body 12 disposed on the base to provide a passenger cabin, a pair of first wheels 20 held by the base to run on upper surfaces 1 a of the rails 1, a pair of second wheels 30 held by the base to run on the upper surfaces 1 a of the rails 1 and spaced from the first wheels in the extending direction of the rails, a pair of thirds wheels 40 held by the base to run on lower surfaces 1 b of the rails 1, four auxiliary wheels 50 held by the base to run on side surfaces 1 c of the rails 1 under each of the first and second wheels, and a motor 2 for driving the first wheels 20. As shown in FIG. 3, the first wheels 20 are positioned between the second wheels 30 and the third wheels 40 in the extending direction of the rails 1, and each of the second wheels 30 is held by the base 11 through a cushioning member 32 such as a coil spring.

As shown in FIGS. 4 and 5, the rail 1 has an H(I)-shaped cross section, which is composed of a web 2 of a perpendicular plate, and flanges 3 of horizontal plates integrally connected to upper and lower ends of the web. By connecting the rails by use of joining members (not shown) in the extending direction, a desired rail track can be obtained.

As shown in FIGS. 1 and 2, the body 12 has a space for passengers therein, bumpers 13 at its front and rear ends, and windows 14 formed in the left, right, front and rear sides. In this embodiment, passenger doors 15 are formed above the first wheels, and seats 16 are mainly arranged on the base 11 above the second wheels 30.

As shown in FIG. 4, the first wheels 20 used in this embodiment are tires made of an elastic material such as rubber tires. A rotating shaft 21 for coupling between the pair of the first wheels is supported by bearing portions 24 mounted on the bottom surface of the base 11. In addition, a rotational output of the motor 22 mounted on the base is transmitted to the rotating shaft 21 of the first wheels through a power transmission unit including a belt 25 and pulleys 26. Thus, the first wheels 20 are drive wheels in this embodiment.

As shown in FIG. 5 the second wheels 30 used in this embodiment are tires made of an elastic material such as rubber tires. A shaft 31 for coupling between the pair of the second wheels 30 are held by bearing portions 33 mounted on the bottom surface of the base 11. In addition, the bearing portions 33 are coupled to the base through the cushioning members 32. Thereby, when the cushioning members 32 are elastically deformed, the vehicle can take an inclined posture such that the second wheel side of the base 11 comes close to the rails. In this embodiment, since the rotational output of the motor 22 is not transmitted to the second wheels 30, the second wheels are non-drive wheels.

As shown in FIGS. 3 and 4, the third wheels 40 used in this embodiment are ties made of an elastic material such as rubber tires. The pair of the third wheels 40 are rotatably held in the vicinity of ends of a pair of frames 41 hanging from both sides of the base 11. A length of this holding member is determined such that the third wheels 40 contact the lower surfaces 1 b of the rails 1 when the first wheels 20 contact the upper surfaces 1 a of the rails 1. In the figures, the numeral 42 designates a reinforcing member extending between the bottom ends of the frames 41 and bottom ends of auxiliary frames 51 for holding auxiliary wheels 50 described later.

In this embodiment, the auxiliary wheels 50 are tires made of an elastic material such as rubber tires. Each of the auxiliary wheels 50 is rotatably held in the vicinity of a bottom end of the auxiliary frame 51 to run on the side surface 1 c of the rail 1, i.e., a surface of the web 2. The first wheels 20 and the second wheels 30 are guided by the auxiliary wheels to prevent derailment. In this embodiment, a part of the frame 41 for holding the third wheel 40 is used as a part of the auxiliary frame for holding the auxiliary wheel 50 disposed under the first wheel.

Referring to FIGS. 6A and 6B, the mechanism of generating the gripping forces of the above-described vehicle 10 of the present invention on the rails 1 is explained below. As shown in FIG. 6A, when the vehicle 10 is in a horizontal posture on the rails 1, the rails 1 are caught between the third wheels 40 contacting the lower surfaces of the rails 1 and the first and second wheels (20, 30) contacting the upper surfaces of the rails, so that the gripping forces can be stably obtained between the rails 1 and the first wheels 20 of the drive wheels.

On the other hand, when passengers sit on the seats 16 positioned above the second wheels 30, as shown in FIG. 6B, the elastic deformation of the cushioning members 32 is caused by the total weight of the vehicle and the passengers, so that the vehicle takes an inclined posture that the second wheel side of the base 11 comes close to the rails 1. At this time, according to the principle of leverage or a seesaw motion with fulcrums of the first wheels 20, the third wheel side of the base 11 receives a force in a direction spaced away from the rails, i.e., the upward direction. However, the upward movement of the third wheel side of the base 11 is prevented because the third wheels supported by the frames 41 are pressed against the lower surfaces of the rails. The forces of pressing the third wheels against the rails work in the direction of reducing the distance between the first wheels and the third wheels. Consequently, the first wheels are also pressed against the rails. Thus, when the vehicle takes the inclined posture due to the elastic deformation of the cushioning members 32, it is possible to increase the gripping forces of the first wheels, i.e., the drive wheels on the rail.

In the above explanation, the inclined posture of the vehicle is drawn with exaggeration to easily understand the present invention. In this embodiment, since the rubber tires are used as the first to third wheels, the elastic deformation of these tires contributes to the inclined posture of the vehicle. When metal wheels are used in place of the rubber tires, it is preferred that the first wheels and/or the third wheels are held by the base through cushioning members such as coil springs. Thereby, the inclined posture of the vehicle can be obtained in a similar manner to the above.

When the vehicle 10 runs in an inclined section of the rails 1, the first wheels 20 are the front wheels in the case of ascending the inclined section, and the second wheels 30 are the front wheels in the case of descending the inclined section, as shown in FIG. 7. In this case, since the center of gravity of the vehicle positioned at the side of the second wheels 30, a larger weight is applied to the cushioning member, so that the vehicle can easily take the inclined posture. Therefore, increased gripping forces can be obtained between the rails 1 and the first wheels 20 of the drive wheels at the inclined section of the rails, as compared with the case that the vehicle runs in a horizontal section of the rails. From this viewpoint, it is preferred that the distance between the first wheel and the center of gravity of the vehicle in the running state is longer than the distance between the second wheel and the center of gravity, and shorter than the distance between the third wheel and the center of gravity. In brief, the center of gravity of the vehicle in the running state is preferably positioned in the vicinity of the second wheel. In addition, the deformation amounts of the cushioning members 32 increase depending on the weight of the vehicle (including loads). This means that the gripping forces of the first wheels 20 (i.e., the drive wheels) can be increased depending on the vehicle's weight. Thus, according to the present invention, it is possible to provide a moderate gripping force in response to a change of the vehicle's weight by use of the cushioning member having a desired elastic deformation capability.

The vehicle 10 described above has a single third wheel 40 on each of the rails 1. To further improve the gripping force, the number of the third wheels 40 may be increased. For example, as shown in FIG. 8, a pair of third wheels 40 spaced from each other in the extending direction of the rail may be rotatably held in the vicinity of an end of the frame 41 hanging from the vehicle 10. That is, the pair of the third wheels 40 are rotatably supported at opposite ends of a supporting member 43. The supporting member 43 is mounted at its center portion on the frame 41 by use of a pin 45. As shown by the arrows in FIG. 8, the supporting member 43 is pivotally supported about the pin 45. Therefore, even when the vehicle takes the inclined posture, all of the third wheels 40 can stably contact the lower surface 1 b of the rail 1.

In the above components, when the vehicle 10 takes the inclined posture due to the elastic deformation of the cushioning member 32 caused by the vehicle's weight, all of the third wheels 40 can be pressed against the lower surfaces of the rails 1 according to the principle of leverage, as in the case of FIG. 6B. Consequently, the gripping forces of catching the rails between the first wheels 20 and the third wheels 40 can be obtained. In addition, the gripping forces can be further improved by an increase in contact areas between the third wheels and the rails, as compared with the case of FIG. 6B.

The above embodiment is directed to the vehicle for running on the rails in parallel to each other. However, the vehicle may have the capability of running on a single rail. Needless to say, the vehicle for running on a monorail can provide the same effects as the above embodiment.

The above explanations about the vehicle for running on the rails and the rail system according to the preferred embodiments of the present invention should be interpreted to understand the technical concept of the present invention. Therefore, they do not mean to limit the scope of the invention. In addition, the components of the present invention may be modified, if necessary, on the condition that the modification is in the technical concept of the present invention.

INDUSTRIAL APPLICABILITY

As understood from the above embodiments, the vehicle of the present invention is characterized by having the third wheels rotatable on the lower surfaces of the rails in addition to the first and second wheels rotatable on the uppers surface of the rails, disposing the first wheels between the second wheels and the third wheels in the extending direction of the rails, and holding the second wheels through the cushioning members. Therefore, when the vehicle inclines due to the elastic deformation of the cushioning members, the third wheels are pressed against the lower surfaces of the rails according to the principle of leverage, thereby increasing the gripping forces of the first wheels and the third wheels on the rails. In addition, since the gripping forces change according to the total weight of the vehicle, it is possible to prevent slippage of the drive wheels and provide smooth running of the vehicle by use of a relatively simple mechanism without mounting an expensive device for controlling the grip force in the vehicle. Consequently, it is expected to be utilized as a short distance transport means for passengers or freights as well as an amusement ride or a traffic means in amusement and theme parks. 

1. A vehicle for running on a rail comprising: a base; a pair of first and second wheels held by said base to be rotatable on an upper surface of said rail and spaced from each other in an extending direction of said rail; a third wheel held by said base to be rotatable on a lower surface of said rail; a motor for driving at least one of the first and second wheels; wherein the first wheel is positioned between the second wheel and the third wheel in the extending direction of said rail, and the second wheel is held by said base through a cushioning member.
 2. The vehicle as set forth in claim 1, wherein the third wheel comprises at least two wheels spaced from each other in the extending direction of said rail.
 3. The vehicle as set forth in claim 1, wherein the first wheel comprises a tire made of an elastic material.
 4. The vehicle as set forth in claim 1, comprising an auxiliary wheel held by said base to be rotatable on a side surface of said rail under at least one of the first and second wheels.
 5. The vehicle as set forth in claim 1, wherein a distance between the first wheel and a center of gravity of the vehicle in a running state is greater than the distance between the second wheel and the center of gravity, and shorter than the distance between the third wheel and the center of gravity. 